# -*- coding: utf-8 -*-

"""
created by huash06 at 2015-04-13 10:53

Given a binary tree and a sum, determine if the tree has a root-to-leaf path
such that adding up all the values along the path equals the given sum.

For example:
Given the below binary tree and sum = 22,
              5
             / \
            4   8
           /   / \
          11  13  4
         /  \      \
        7    2      1
return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.

"""
__author__ = 'huash06'

import sys
import os




# Definition for a  binary tree node
class TreeNode:
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None

class Solution:
    # @param root, a tree node
    # @param sum, an integer
    # @return a boolean
    def hasPathSum(self, root, sum):
        if not root:
            return False
        if not root.left and not root.right and sum == root.val:
            return True

        if self.hasPathSum(root.left, sum-root.val):
            return True
        if self.hasPathSum(root.right, sum-root.val):
            return True
        return False



s = Solution()
print()
